Design of slot radiating RF planar sensor for homogeneity check of dielectric discontinuity

In this paper, a 2.8-GHz RF planar sensor with radiating slots is proposed for effective checking of discontinuity in homogeneous dielectric samples. The slots etched in the ground plane reduce the effective area for sample placement, which increases in the case of a conventional ring at the desired frequency. Several forms of discontinuity are analyzed and measured with the help of varying geometrical configurations of Teflon, wood, and polyethylene samples with varying permittivity. It is observed that due to the uniform distribution of fields among all the radiating slots any sort of configurational discontinuity is detected by the sensor in terms of the shift in resonant frequency and S-21 transmission notch. The simulations are carried out using CST-MWS and the equivalent model is developed using ADS. The numerical analysis is carried out using Origin software and the measurement is carried out using Taconic TLY-5 substrate by photolithographic etching.